I am laying out a board that connects to another board via 2 50 pin headers. (2 rows x 25 pins each on 0.100" spacings). I've got a ccouple questions....
Question 1: The first header is "normal", ie pin 1 is in the upper left corner of the header layout. No problems there. The second header is "mirrored", ie pin 1 is in the upper right corner of the header layout. It is like this because the board developer originally intended for one board to be attached to each header and header 2 was supposed to be used on the underside of the board. Thus, from the underside of the board pin 1 is in the traditional upper left location, but on the topside it is in the mirrored location. On the board that I purchased, both headers are soldered to the upper side. I am attaching my board from the upper side only, thus the second headers has an unconventional pinout. How do I define a footprint with a "mirrored" pinout (without renumbering the pinout) ? Or will renumbering the pinout be the easiest way ? I'd like not to renumber the pinout for 2 reasons: a) the schematic for the purchased board uses the underside pin numbers. b) someday I might build a board that uses only the second header and mounts underneath the purchased board. Question 2: I am using the 50 pin connectors as templates for my new connectors. (I am going to modify the pin names, etc. because I will be making a number of boards to attach to these headers.) Specifically, I am using header50-3.sym. I've noticed that this and other 50 pin headers do not have a defined footprint in the symbol. Why is this ? Does the user define the footprint when it is used in the schematic to make it more versatile ? Am I missing something ? Thanks ! -- Kim Lux, Diesel Research Inc.
